1. Convulsant properties of L-glutamic acid di-tert butyl ester
W J Freed, E H Ghoz, S Crump Neurobehav Toxicol Teratol. 1985 May-Jun;7(3):275-8.
Glutamic acid di-tert butyl ester (GTBE) was found to have a pronounced convulsant effect in mice and rats, producing recurrent clonic convulsions combined with postural and respiratory disturbances in a dosage of 0.5 mmol/kg (148 mg/kg). Tert-butyl ester derivatives of aspartic acid and alanine, and glutamic acid gamma-benzyl ester did not produce seizures. Various other glutamate esters, such as glutamic acid diethyl ester and glutamic acid dimethyl ester, have previously been found to have anticonvulsant effects, and also do not induce seizures. It is suggested that glutamic acid di-tert butyl ester may have specific pharmacological properties which differ from those of other known convulsant drugs.
2. Therapeutic melanoma inhibition by local micelle-mediated cyclic nucleotide repression
Kerstin Johann, et al. Nat Commun. 2021 Oct 13;12(1):5981. doi: 10.1038/s41467-021-26269-w.
The acidic tumor microenvironment in melanoma drives immune evasion by up-regulating cyclic adenosine monophosphate (cAMP) in tumor-infiltrating monocytes. Here we show that the release of non-toxic concentrations of an adenylate cyclase (AC) inhibitor from poly(sarcosine)-block-poly(L-glutamic acid γ-benzyl ester) (polypept(o)id) copolymer micelles restores antitumor immunity. In combination with selective, non-therapeutic regulatory T cell depletion, AC inhibitor micelles achieve a complete remission of established B16-F10-OVA tumors. Single-cell sequencing of melanoma-infiltrating immune cells shows that AC inhibitor micelles reduce the number of anti-inflammatory myeloid cells and checkpoint receptor expression on T cells. AC inhibitor micelles thus represent an immunotherapeutic measure to counteract melanoma immune escape.
3. Aminated Graphene-Graft-Oligo(Glutamic Acid) /Poly(ε-Caprolactone) Composites: Preparation, Characterization and Biological Evaluation
Mariia Stepanova, et al. Polymers (Basel). 2021 Aug 7;13(16):2628. doi: 10.3390/polym13162628.
Biodegradable and biocompatible composites are of great interest as biomedical materials for various regeneration processes such as the regeneration of bones, cartilage and soft tissues. Modification of the filler surface can improve its compatibility with the polymer matrix, and, as a result, the characteristics and properties of composite materials. This work is devoted to the synthesis and modification of aminated graphene with oligomers of glutamic acid and their use for the preparation of composite materials based on poly(ε-caprolactone). Ring-opening polymerization of N-carboxyanhydride of glutamic acid γ-benzyl ester was used to graft oligomers of glutamic acid from the surface of aminated graphene. The success of the modification was confirmed by Fourier-transform infrared and X-ray photoelectron spectroscopy as well as thermogravimetric analysis. In addition, the dispersions of neat and modified aminated graphene were analyzed by dynamic and electrophoretic light scattering to monitor changes in the characteristics due to modification. The poly(ε-caprolactone) films filled with neat and modified aminated graphene were manufactured and carefully characterized for their mechanical and biological properties. Grafting of glutamic acid oligomers from the surface of aminated graphene improved the distribution of the filler in the polymer matrix that, in turn, positively affected the mechanical properties of composite materials in comparison to ones containing the unmodified filler. Moreover, the modification improved the biocompatibility of the filler with human MG-63 osteoblast-like cells.